Analysis seminar

Hanfeng Li, The State University of New York, Buffalo

Entropy and L2-torsion”

Given any countable discrete group G and any countable left module M of the integral group ring of G, one may consider the natural action of G on the Pontryagin dual of M. Under suitable conditions, the entropy of this action and the L2-torsion of M are defined. I will discuss the relation between the entropy and the L2-torsion, and indicate how this confirms the conjecture of Wolfgang Luck that any nontrivial amenable group admitting a finite classifying space has trivial L2-torsion. This is joint work with Andreas Thom.